The invention relates to a collector for moving equipment, such as overhead cranes, electric hoists, etc. Such collectors are incorporated as a wagon supported by sliding supports or wheels in a U-profile rail which is mounted upside down and contains extruded conductor holders. The rail profile contains a number of conductors. A power cable connects the wagon(s) to a connection box which moves along with the moving equipment. A connecting chain pulls the wagon along with the equipment.
The wagon has carbon brushes mounted in the sides to pick-up the conductors"" tension. The carbon brushes move in the rail""s pick-up chambers. Configurations of four/six or five/seven conductors are possible; whereby the wagon has two or three carbon brushes, respectively projecting from both sides. In the latter two cases, an additional carbon brush projects up to contact a conductor in the top of the rail profile.
For stability reasons, the carbon brushes are mounted in pairs at the same level. Due to the carbon brush""s length with respect to the wagon""s width (also determined by the profile) this is only possible by sequentially placing the carbon brushes in the transport direction. To this end, the wagon (whose dimensions are kept to a minimum) contains a pick-up chamber orientated to the one side at the front part and a pick-up chamber orientated to the other side at the back part. This type of wagon has been in use for many years.
However, the stability of these wagons is not optimum. The wagon moves slightly around the central axis due to the asymmetric positioning of the carbon brushes with respect to the central axis. This is, especially, the case when three carbon brushes are mounted on either side of the wagon. As a result, the parts of the wagon projecting from the bottom of the rail, the so-called bow, fastened to the bottom of the power cable (containing the conductors to the cable connectors near the carbon brushes) rub against the inner ridges of the profile""s extruded conductor holders, eventually leading to failure. Another consequence of the wagon""s off-centered position is that the carbon brushes wear unevenly, significantly reducing their life span. To prevent this, additional small (because of the limited space) horizontal side wheels are occasionally placed on the wagon. However, these small wheels often cannot handle the high number of revolutions. In addition, they require additional assembly labor and material.
The invention is aimed at improving this in an efficient way. To this end, the invention consists of a collector for moving equipment (such as overhead cranes), with a wagon equipped with means for picking up power using sliding contacts over a number of fixed conductors in a rail profile. The contact means transfer power from a number of cable connectors in the wagon with electric wires from a power cable connected for the installation""s power supply. The wagon contains at least two sequentially sub-contact means on either side of the vertical axis on one side of the wagon.
This stabilizes the wagon at least in one tilt direction because two stabilization points are mounted at the same level on one side of the wagon. In addition, the contact with the conductors is more reliable because, should one (sub-) contact means on one side of the wagon fail to make contact, the other one will make contact. This is very important for the data line""s power contacts.
In the preferred configuration, for the two conductors at the same level on either side of the wagon, at least two sub-contact means are fitted sequentially to the wagon on either side of the vertical central axis. The presence of two (sub-) contact means at one level on either side of the wagon prevents the wagon from tilting around an axis with a vertical component.
In the preferred configuration, the sub-contact means on both sides of the wagon are located symmetrically with respect to a vertical plane which is at right angles to the transport direction and further increases stability.
The sub-contact means are preferably placed in the collector""s pick-up chambers. These pick-up chambers can be used without further mechanical intervention in the wagon""s composing parts and take-up as much room as the normal carbon brush""s pick-up chamber.
An additional chamber is created for extra, vertical guide wheels (when required) to increase the wagon""s stability in the vertical plane by omitting the side wheels.
The contact means are generally formed as carbon brushes and the sub-contact means each form an equal part.
Preferably three conductors are mounted on each side. The shared contact means (from a vertical point of view) are situated between the other two contact means. As a rule, the data line goes through the middle conductor(s) to ensure good contact.
To increase stability and the contact""s reliability, it is recommended that at least one of the other contact means is shared at another level.
The conductors"" wagons generally have a housing consisting of two halves; one placed against the other in a vertical plane and fixed using a bolt through the wagon. This bolt can be replaced by an additional axis. The power cable passes through the housing""s bow parts. The bow parts have a screw thread at the bottom to fix a tension relief collar for the power cable.
When the bow is about to wear through, as a result of the intensive contact with the rail profile""s ridges containing the conductors, the entire housing must be replaced resulting in relatively high costs. Another disadvantage is apparent when trying to connect the power cable to the wagon in situ. The entire housing must be opened up to correctly manipulate the electric wires.
This invention is aimed at improving this situation. To this end, the invention consists of a collector for moving equipment (such as overhead cranes), with a wagon equipped with means for picking up power using sliding contacts over a number of fixed conductors in a rail profile.
The contact means transfer power from a number of cable connectors in the wagon with electric wires from a power cable connected for the installation""s power supply. The wagon contains a housing with a bow on the underside, projecting out of the profile for the power cable""s passage. The bow can be detached from the housing.
When the bow is worn-out, it can be easily replaced. To connect the power cable, the bow is moved to the end of the housing, the electric wires are fed into the housing from underneath and connected to the cable connectors. Finally, the bow is fixed to the housing.
In the preferred configuration, the bow has two bow parts; one placed against the other in a vertical plane. In doing so, the wagon""s bow can be detached without releasing the power cable.
In the preferred configuration, the bow parts are held together by an axis through both bow parts. Support wheels can be mounted onto the axis, when required. The existing wagon has such an axis but in the new configuration, the axis serves an extra purpose, i.e. it keeps the bow parts together.
In the preferred configuration, two bow parts are also held together by the tension relief collar. The existing wagon has a gland nut screwed onto the bow. The tension relief collar, which is clicked into place, now serves an extra purpose, i.e. it keeps the bow parts together.
The bow is preferably flat and determines the area for the conductors from the power cable with an oblong cross-section in the horizontal plane, originating at the bow""s front edge and ending at the bow""s back edge. The bow""s internal length in the transport direction is sufficient to place at least seven 6 mm2 electric wires next to each other. With this number of electric wires, the bow can still be flat reducing the chances of wear as a result of friction on the U profile""s ridges.
Generally, each carbon brush can pass a current intensity of maximum 35 A. Several wagons with carbon brushes on the same side and at the same level can be coupled to increase the current intensity. A current intensity of 70 A and 100 A is achievable with two or respectively, three wagons.
The wagons are coupled using a rectangular steel connecting plate underneath the wagons connecting the wagon""s bows. To move the wagons closer together, the guide wheels are removed from both sides of one wagon.
Special parts are required to couple the wagons; for example, the connecting plate which must be tuned to two or three wagon lengths. The assembly requires quite some effort as does the disassembly when parts of the wagon (such as the housing) need to be replaced. In addition, the wheels between the wagons can damage the other wagon""s housing (as a result of possible flexing with respect to the other wagon). As a result, the housing must be replaced frequently. The collectors can tilt because the wheel sets are loose on one side and because of the possible deviation in the alignment. The bow""s friction against the rail results in wear and damage to the separate collectors.
The invention is aimed at improving this. To this end, the invention consists of a collector for moving equipment (such as overhead cranes), with a wagon equipped with means for picking up power using sliding contacts over a number of fixed conductors in a rail profile. The contact means transfer power from a number of cable connectors in the wagon with electric wires from a power cable connected for the installation""s power supply. Wheels are fixed at the front and at the back of the wagon to guide it in the rail profile. The wagon and the wheels are respectively equipped with co-operating, detachable first and second click connectors. The collector is equipped with a coupling with second coupling means on opposite sides.
The wheels can be released easily and quickly from the wagon and replaced with the coupling part. The wagons are directly linked within the rail profile which increases the running stability. The wheels are also easily replaced with similar wheels, other types of wheels or wheel combinations.
The connector means are preferably dovetail-shaped and/or click connectors to provide simple and reliable assembly.